/*
             MyUSB Library
     Copyright (C) Dean Camera, 2008.
              
  dean [at] fourwalledcubicle [dot] com
      www.fourwalledcubicle.com

 Released under the LGPL Licence, Version 3
*/

/** Library events module. This module contains macros and functions relating to the management of library
 *  events, which are small pieces of code similar to ISRs which are run when a given condition is met. Each
 *  event can be fired from multiple places in the user or library code, which may or may not be inside an ISR,
 *  thus each handler should be written to be as small and fast as possible to prevent possible problems.
 *
 *  Events can be hooked by the user application using the EVENT_HANDLER() and HANDLES_EVENT() macros. If an
 *  event with no associated handler is fired within the library, it by default fires an internal empty stub
 *  function. This is achieved through the use of the GCC compiler's "alias" attribute.
 *
 *  Each event must only have one associated event handler, but can be raised by multiple sources.
 */
 
#ifndef __USB_EVENTS_H__
#define __USB_EVENTS_H__

	/* Includes: */
		#include <avr/io.h>
		
		#include "../../../Common/Common.h"
		#include "../LowLevel/USBMode.h"

	/* Enable C linkage for C++ Compilers: */
		#if defined(__cplusplus)
			extern "C" {
		#endif

	/* Public Interface - May be used in end-application: */
		/* Macros: */
			/** Raises a given event name, with the specified parameters. For events with no parameters the
			 *  only argument to the macro is the event name, events with parameters list the parameter values
			 *  after the name as a comma seperated list.
			 *
			 *  When a given event is fired, its corresponding event handler code is executed.
			 *
			 *  Usage Examples:
			 *  \code
			 *  // Raise the USB_VBUSChange event, which takes no parameters
			 *  RAISE_EVENT(USB_VBUSChange);
			 *
			 *  // Raise the USB_UnhandledControlPacket event which takes two parameters
			 *  RAISE_EVENT(USB_UnhandledControlPacket, 0, 1);
			 *  \endcode
			 *
			 *  \see RAISES_EVENT()
			 */
			#define RAISE_EVENT(e, ...)                 Event_ ## e (__VA_ARGS__)

			/** Indicates that a given module can raise a given event. This is the equivelent of putting the
			 *  event function's prototype into the module, but in a cleaner way. Each event which may be
			 *  fired via the RAISE_EVENT macro in the module should have an accompanying RAISES_EVENT
			 *  prototype in the module's header file.
			 *
			 *  Usage Examples:
			 *  \code
			 *  // Module can raise the USB_VBUSChange event
			 *  RAISES_EVENT(USB_VBUSChange);
			 *
			 *  // ...
			 *  // Inside a block of code in a function of the module, raise the USB_VBUSChange event
			 *  RAISE_EVENT(USB_VBUSChange);
			 *  \endcode
			 *
			 *  \see RAISE_EVENT()
			 */
			#define RAISES_EVENT(e)                     HANDLES_EVENT(e)

			/** Defines an event handler for the given event. Event handlers should be short in length, as they
			 *  may be raised from inside an ISR. The user application can react to each event as it sees fit,
			 *  such as logging the event, indicating the change to the user or performing some other action.
			 *
			 *  Only one event handler may be defined in any user project for each individual event. Events may
			 *  or may not have parameters - for each event, refer to its documentation elsewhere in this module
			 *  to determine the presense and purpose of any event parameters.
			 *
			 *  Usage Example:
			 *  \code
			 *  // Create an event handler for the USB_VBUSChange event
			 *  EVENT_HANDLER(USB_VBUSChange)
			 *  {
			 *      // Code to execute when the VBUS level changes
			 *  }
			 *  \endcode
			 *
			 *  \see HANDLES_EVENT()
			 */
			#define EVENT_HANDLER(e)                    void Event_ ## e e ## _P
			
			/** Indicates that a given module handles an event. This is the equivelent of putting the
			 *  event function's prototype into the module, but in a cleaner way. Each event which may be
			 *  handled via the EVENT_HANDLER macro in the module should have an accompanying HANDLES_EVENT
			 *  prototype in the module's header file.
			 *
			 *  Usage Examples:
			 *  \code
			 *  // Module handles the USB_VBUSChange event
			 *  HANDLES_EVENT(USB_VBUSChange);
			 *
			 *  // Create the USB_VBUSChange event handler
			 *  EVENT_HANDLER(USB_VBUSChange)
			 *  {
			 *      // Event handler code here
			 *  }
			 *  \endcode
			 *
			 *  \see EVENT_HANDLER()
			 */
			#define HANDLES_EVENT(e)                    EVENT_HANDLER(e)
			
		/* Psudo-Functions for Doxygen: */
		#if defined(__DOXYGEN__)
			/** Event for VBUS level change. This event fires when the VBUS line of the USB AVR changes from
			 *  high to low or vice-versa.
			 *
			 *  \note This event is only avaliable on USB AVR models which support VBUS notification interrupts.
			 */
			void USB_VBUSChange(void);

			/** Event for VBUS attachment. This event fires when the VBUS line of the USB AVR changes from
			 *  low to high, signalling the attachment of the USB device to a host, before the enumeration
			 *  process has begun.
			 *
			 *  \note This event is only avaliable on USB AVR models which support VBUS notification interrupts.
			 */
			void USB_VBUSConnect(void);

			/** Event for VBUS detachment. This event fires when the VBUS line of the USB AVR changes from
			 *  high to low, signalling the USB device has been removed from a host whether it has been enumerated
			 *  or not.
			 *
			 *  \note This event is only avaliable on USB AVR models which support VBUS notification interrupts.
			 */
			void USB_VBUSDisconnect(void);

			/** Event for USB device connection. This event fires when the AVR is in USB host mode and a device
			 *  has been attached (but not yet fully enumerated), or when in device mode and the device is connected
			 *  to a host, beginning the enumeration process.
			 *
			 *  When in device mode, this can be used to progmatically start the USB management task to reduce
			 *  CPU usage.
			 *
			 *  \see USBTask.h for more information on the USB management task and reducing CPU usage.
			 */
			void USB_Connect(void);

			/** Event for USB device disconnection. This event fires when the AVR is in USB host mode and an
			 *  attached and enumerated device has been disconnected, or when in device mode and the device is
			 *  disconnected from the host.
			 *
			 *  When in device mode, this can be used to progmatically stop the USB management task to reduce
			 *  CPU usage.
			 *
			 *  \see USBTask.h for more information on the USB management task and reducing CPU usage.
			 */
			void USB_Disconnect(void);
			
			/** Event for USB device power on failure. This event fires when the USB interface fails to
			 *  initialize correctly due to a hardware or software fault.
			 *
			 *  \param ErrorCode  Error code indicating the failure reason, a value in USB_PowerOnErrorCodes_t
			 *                    located in LowLevel.h.
			 */
			void USB_PowerOnFail(const uint8_t ErrorCode);

			/** Event for USB mode pin level change. This event fires when the USB interface is set to dual role
			 *  mode, and the UID pin level has changed to indicate a new mode (device or host). This event fires
			 *  before the mode is switched to the newly indicated mode.
			 *
			 *  \note This event only exists on USB AVR models which support dual role modes.
			 *
			 *  \note This event does not exist if the USB_DEVICE_ONLY or USB_HOST_ONLY tokens have been supplied
			 *        to the compiler (see LowLevel.h documentation).
			 */
			void USB_UIDChange(void);

			/** Event for USB host error. This event fires when a hardware fault has occurred whilst the USB
			 *  interface is in host mode.
			 *
			 *  \param ErrorCode  Error code indicating the failure reason, a value in USB_Host_ErrorCodes_t
			 *                    located in Host.h.
			 *
			 *  \note This event only exists on USB AVR models which supports host mode.
			 *
			 *  \note This event does not exist if the USB_DEVICE_ONLY token is supplied to the compiler (see
			 *        LowLevel.h documentation).
			 */
			void USB_HostError(const uint8_t ErrorCode);
			
			/** Event for USB device attachment. This event fires when a the USB interface is in host mode, and
			 *  a USB device has been connected to the USB interface. This is interrupt driven, thus fires before
			 *  the standard USB_DeviceConnect event and so can be used to programatically start the USB management
			 *  task to reduce CPU consumption.
			 *
			 *  \note This event only exists on USB AVR models which supports host mode.
			 *
			 *  \note This event does not exist if the USB_DEVICE_ONLY token is supplied to the compiler (see
			 *        LowLevel.h documentation).
			 *
			 *  \see USBTask.h for more information on the USB management task and reducing CPU usage.
			 */
			void USB_DeviceAttached(void);

			/** Event for USB device removal. This event fires when a the USB interface is in host mode, and
			 *  a USB device has been removed the USB interface whether or not it has been enumerated. This
			 *  can be used to programatically stop the USB management task to reduce CPU consumption.
			 *
			 *  \note This event only exists on USB AVR models which supports host mode.
			 *
			 *  \note This event does not exist if the USB_DEVICE_ONLY token is supplied to the compiler (see
			 *        LowLevel.h documentation).
			 *
			 *  \see USBTask.h for more information on the USB management task and reducing CPU usage.
			 */
			void USB_DeviceUnattached(void);
			
			/** Event for USB device enumeration failure. This event fires when a the USB interface is
			 *  in host mode, and an attached USB device has failed to enumerate completely.
			 *
			 *  \param ErrorCode  Error code indicating the failure reason, a value in 
			 *                    USB_Host_EnumerationErrorCodes_t located in Host.h.
			 *
			 *  \note This event only exists on USB AVR models which supports host mode.
			 *
			 *  \note This event does not exist if the USB_DEVICE_ONLY token is supplied to the compiler (see
			 *        LowLevel.h documentation).
			 */
			void USB_DeviceEnumerationFailed(const uint8_t ErrorCode);

			/** Event for USB device enumeration completion. This event fires when a the USB interface is
			 *  in host mode and an attached USB device has been completely enumerated and is ready to be
			 *  controlled by the user application, or when the library is in device mode, and the Host
			 *  has finished enumerating the device.
			 */
			void USB_DeviceEnumerationComplete(void);

			/** Event for unhandled control requests. This event fires when a the USB host issues a control
			 *  request to the control endpoint (address 0) that the library does not handle. This may either
			 *  be a standard request that the library has no handler code for, or a class specific request
			 *  issued to the device which must be handled appropriately.
			 *
			 *  \param Request      Request value, indicating what command the host has issued.
			 *  \param RequestType  Mask indicating the request data direction (if any), type and recipient.
			 *
			 *  \note This event does not exist if the USB_HOST_ONLY token is supplied to the compiler (see
			 *        LowLevel.h documentation).
			 *
			 *  \note Requests should be handled in the same manner as described in the USB 2.0 Specification,
			 *        or appropriate class' specification. In all instances, the library has already read the
			 *        request bmRequestType and bRequest values out (into the Request and RequestType parameters
			 *        respectively) so that it can correctly determine if it is able to handle the request
			 *        internally, or hand off the request to the user application via this event. Other request
			 *        parameters (wValue, wIndex, wLength, and Data) remain in the control endpoint bank until
			 *        read out by the user application for processing.
			 */
			void USB_UnhandledControlPacket(const uint8_t Request, const uint8_t RequestType);

			/** Event for USB configuration number changed. This event fires when a the USB host changes the
			 *  selected configuration number while in device mode. This event should be hooked in device
			 *  applications to create the endpoints and configure the device for the selected configuration.
			 *
			 *  This event fires after the value of USB_ConfigurationNumber has been changed.
			 *
			 *  \note This event does not exist if the USB_HOST_ONLY token is supplied to the compiler (see
			 *        LowLevel.h documentation).
			 */
			void USB_ConfigurationChanged(void);

			/** Event for USB suspend. This event fires when a the USB host suspends the device by halting its
			 *  transmission of Start Of Frame pulses to the device. This is generally hooked in order to move
			 *  the device over to a low power state until the host wakes up the device.
			 *
			 *  \note This event does not exist if the USB_HOST_ONLY token is supplied to the compiler (see
			 *        LowLevel.h documentation).
			 *
			 *  \see USB_WakeUp() event for accompanying Wake Up event.
			 */
			void USB_Suspend(void);

			/** Event for USB wake up. This event fires when a the USB interface is suspended while in device
			 *  mode, and the host wakes up the device by supplying Start Of Frame pulses. This is generally
			 *  hooked to pull the user application out of a lowe power state and back into normal operating
			 *  mode.
			 *
			 *  \note This event does not exist if the USB_HOST_ONLY token is supplied to the compiler (see
			 *        LowLevel.h documentation).
			 *
			 *  \see USB_Suspend() event for accompanying Suspend event.
			 */
			void USB_WakeUp(void);

			/** Event for USB interface reset. This event fires when a the USB interface is in device mode, and
			 *  a the USB host requests that the device reset its interface. This is generally hooked so that
			 *  the USB control endpoint can be switched to interrupt driven mode, by selecting it and calling
			 *  USB_INT_Enable(ENDPOINT_INT_SETUP).
			 *
			 *  \note This event does not exist if the USB_HOST_ONLY token is supplied to the compiler (see
			 *        LowLevel.h documentation).
			 */
			void USB_Reset(void);
			
			/** Event for USB device mode error. This event fires when the USB interface is in device mode,
			 *  and an error occurs which prevents it from operating normally.
			 *
			 *  \param ErrorCode  Error code indicating the source of the error. One of the values in the
			 *                    USB_Device_ErrorCodes_t enum located in Device.h.
			 *
			 *  \note This event does not exist if the USB_HOST_ONLY token is supplied to the compiler (see
			 *        LowLevel.h documentation).
			 */
			void USB_DeviceError(const uint8_t ErrorCode);			
		#endif
		
	/* Private Interface - For use in library only: */
	#if !defined(__DOXYGEN__)
		/* Macros: */
			#define ALIAS_STUB(e)                       EVENT_HANDLER(e) ATTR_WEAK ATTR_ALIAS(__stub)
		
			#if defined(USB_FULL_CONTROLLER)
				#define USB_VBUSChange_P                (void)
				#define USB_VBUSConnect_P               (void)
				#define USB_VBUSDisconnect_P            (void)
			#endif
			
			#define USB_Connect_P                       (void)
			#define USB_Disconnect_P                    (void)
			#define USB_DeviceEnumerationComplete_P     (void)
			
			#if defined(USB_CAN_BE_BOTH)
				#define USB_PowerOnFail_P               (const uint8_t ErrorCode)
				#define USB_UIDChange_P                 (void)
			#endif

			#if defined(USB_CAN_BE_HOST)
				#define USB_HostError_P                 (const uint8_t ErrorCode)
				#define USB_DeviceAttached_P            (void)
				#define USB_DeviceUnattached_P          (void)
				#define USB_DeviceEnumerationFailed_P   (const uint8_t ErrorCode)
			#endif
			
			#if defined(USB_CAN_BE_DEVICE)
				#define USB_UnhandledControlPacket_P    (const uint8_t Request, const uint8_t RequestType)
				#define USB_ConfigurationChanged_P      (void)
				#define USB_Suspend_P                   (void)
				#define USB_WakeUp_P                    (void)
				#define USB_Reset_P                     (void)
				#define USB_DeviceError_P               (const uint8_t ErrorCode)
			#endif

		/* Function Prototypes: */
			#if defined(INCLUDE_FROM_EVENTS_C)
				static void __stub (void) ATTR_CONST;

				#if defined(USB_FULL_CONTROLLER)
				ALIAS_STUB(USB_VBUSChange);
				ALIAS_STUB(USB_VBUSConnect);
				ALIAS_STUB(USB_VBUSDisconnect);
				#endif
				
				ALIAS_STUB(USB_Connect);
				ALIAS_STUB(USB_Disconnect);
				ALIAS_STUB(USB_DeviceEnumerationComplete);
				
				#if defined(USB_CAN_BE_BOTH)
					ALIAS_STUB(USB_PowerOnFail);
					ALIAS_STUB(USB_UIDChange);
				#endif
				
				#if defined(USB_CAN_BE_HOST)
					ALIAS_STUB(USB_HostError);
					ALIAS_STUB(USB_DeviceAttached);
					ALIAS_STUB(USB_DeviceUnattached);
					ALIAS_STUB(USB_DeviceEnumerationFailed);
				#endif

				#if defined(USB_CAN_BE_DEVICE)
					ALIAS_STUB(USB_UnhandledControlPacket);
					ALIAS_STUB(USB_ConfigurationChanged);
					ALIAS_STUB(USB_Suspend);
					ALIAS_STUB(USB_WakeUp);
					ALIAS_STUB(USB_Reset);
					ALIAS_STUB(USB_DeviceError);
				#endif
			#endif
	#endif

	/* Disable C linkage for C++ Compilers: */
		#if defined(__cplusplus)
			}
		#endif
		
#endif
